I. Field of the Invention
The present invention relates to a device for processing a pressure-measurement signal of a combustion chamber of an internal combustion engine with a view to determining an instant of start of combustion. It also relates to a method employed by this device.
II. Description of Related Art
Such a device is the object of the American patent application published under the number U.S. 2003/0145829. In that document, the pressure-measurement signal is processed by means of a wavelet transformation. An analysis of the coefficients of the wavelet transformation of the pressure-measurement signal makes it possible to detect an instant of start of combustion. More precisely, a sudden increase of the absolute values of these coefficients constitutes an indicator of the instant of start of combustion.
Such processing of the pressure-measurement signal, which consumes considerable computing time, is costly and is difficult to install in a traditional engine control computer.